U.S. Secretary of State John Kerry expressed concern Thursday on Egypt's intensified crackdown on the Muslim Brotherhood after declaring the organization a terrorist group.

While in a phone call with Egyptian Minister of Foreign Affairs Nabil Fahmy, Kerry denounced the suicide bombing in Mansuora on Tuesday and the subsequent Thursday bus bombing in Cairo, he expressed reservations on designation the Muslim Broterhood as a terrorist group and the resulting detentions, State Department spokeswoman Jen Psaki said in a statement.

During the phone call, Kerry and Fahmy "agreed that there can be no place for violence in Egypt and that the Egyptian people deserve peace and calm," Psaki said.

In Washington, a U.S. official said that the administration of President Barack Obama was not considering labeling the Muslim Brotherhood as a terrorist organization.

The official said that despite its concerns over the interim government's latest actions, it was not planning to take any action against Egypt.

Egypt attributes the Tuesday attack, which was claimed by a jihadist group, on former president Mohammad Mursi's Muslim Brotherhood.

The Brotherhood has historically been Egypt's best organized political and social movement.

The group still protests almost daily despite the death of more than 1,000 pro-Mursi supporters and the detainment of thousands more, including the organization's top leadership.